the original ```$GOPATH/bin/registry $GOPATH/src/github.com/docker/distribution/cmd/registry/config-example.yml``` leads to the error like
```
Error: unknown command "/Users/EricYang/go/src/github.com/docker/distribution/cmd/registry/config-example.yml" for "registry"
Run 'registry --help' for usage.
```
I think the correct command should be ```registry serve```
Signed-off-by: Eric Yang <EricYang@EricdeMacBook-Pro.local>